Delayed Starting

[Broosedamoose]

Well, here we go again! I guess it's what I should expect for an old truck with 250K miles. It's been starting up fine since finding the 12V coil fuse was corroded and replacing it. Now all of a sudden it has to crank for a bit before starting. A couple times it didn't start at all until I turned the key Off and tried again! I checked the fuse and both the fuse and the socket are fine. When I turn the key to start, it cranks for anywhere from 2 to 5 seconds before it fires up. Sometimes it fires right up though. I can hear the fuel pump run when I turn the key On so it's not that. I tried spraying Starting Fluid in the intake before trying to start it but it still cranked for a couple seconds before starting. I've tried turning the key to the On position for a couple seconds before starting but it makes no difference. I'm afraid I'm going to be out somewhere and then it won't start at all! I checked for codes but there are none. It's hard to check anything because it does start after a few seconds. I'm scratching my head now!

 

[RonD]

Turn the key on and off 3 times and then try to start
Each time key is turned on you get 2 seconds of fuel pump run time, that adds about 10psi to current fuel system pressure

1998-2011 Rangers run on 60psi fuel pressure, key off pressure should hold above 40psi for several MONTHS
For start up you should have at least 25psi at the injectors

One other thing to look for
Computer starts Spark first and then injectors about 1 second later
And computer only starts spark when it has a reliable timing pulse from the Crank Sensor, for timing of the spark
If its taking a few revolutions of the crank to get a stable timing pulse then a slow start would occur

The CEL(check engine light) will tell you if timing pulse is instant
Computer turns OFF the CEL when it has a reliable timing pulse, so if CEL is staying on for a second or two after cranking starts then I would inspect the crank sensor and it's tone wheel on the back of the crank pulley
If the tone wheel gets full of mud or ?? then it may cause slow start, or if crank sensor is too far away it may not generate enough voltage right off the bat

Crank sensors generate their own voltage from being close to the spinning tone wheels teeth, its AC volts and minimum is about 0.5vAC when cranking engine

 

[Broosedamoose]

Well whatever it was, it fixed itself! I had made an appointment to bring it in but for the last three days it's been starting right up. Maybe it was some bad gas or something. I'm just glad I didn't have to spend any more money on it!